Access floor panel and system

ABSTRACT

The invention relates to an access floor panel for use in an access floor system. The floor panel includes a bottom pan, and a core, the core being made from a mineralized fibrous material blended with cement, such as DURISOL™. The floor panel may further include a top pan which is attached to the top edge of the sidewall.

FIELD OF THE INVENTION

[0001] The present invention relates to access floor systems, and more particularly to access floor panels used in access floor systems.

BACKGROUND OF THE INVENTION

[0002] Access floor systems provide a functional floor that is elevated above a lower floor. Typically the elevated floor is composed of removable, rectangular floor panels that are mounted on an understructure affixed to the lower floor. These floor systems are used to cover ducting, power cables, and various other plumbing and electrical services that run underneath, above the lower floor, while still allowing technicians easy access to them for service, by removing the floor panels.

[0003] There is a need for access floor panels that are strong, yet lightweight, unaffected by moisture, and that provide good sound deadening.

SUMMARY OF THE INVENTION

[0004] In a first aspect, the present invention relates to an access floor panel for use in an access floor system. The panel comprises a bottom pan and a core. The bottom pan includes a plate, and the core is secured to the plate. The core is made from a mineralized fibrous material blended with cement.

[0005] The core may be made specifically from DURISOL™.

[0006] The bottom pan may further include a sidewall that projects upwards from the plate and surrounds the core.

[0007] The floor panel may further comprise a top pan which is secured to the core.

[0008] In a second aspect, the present invention relates to a method of making an access floor panel, the method comprising:

[0009] putting a core material into a bottom pan, the core material comprising a mixture of a mineralized fibrous aggregate and a cement binder; and

[0010] molding and curing the core material into a core in the bottom pan.

[0011] In a third aspect, the present invention relates to a method of making an access floor panel, the method comprising:

[0012] providing a pre-cured core that is adapted to fit with a bottom pan, the core comprising a mixture of a mineralized fibrous aggregate and a cement binder; and

[0013] securing the core to said bottom pan.

[0014] In a fourth aspect, the present invention relates to an access flooring system made with the floor panels described above and pedestals for supporting the floor panels above a lower floor. The pedestals have a base, a support post and a panel support piece for supportion a portion of at least one of the floor panels.

DESCRIPTION OF THE DRAWINGS

[0015] The present invention will now be described by way of example only, with reference to the drawings in which:

[0016]FIG. 1 is an isometric view of an access floor panel in accordance with a first preferred embodiment of the present invention;

[0017]FIG. 2 is a sectional side view of the floor panel in FIG. 1;

[0018]FIG. 3 is a sectional side view of a floor panel in FIG. 1 with optional exterior reinforcing bars;

[0019]FIG. 4 is a sectional side view of a portion of the floor panel in FIG. 1, with an optional key and groove mating system;

[0020]FIG. 5 is an isometric view of an access flooring system showing a plurality of pedestals for supporting a floor panel in accordance with the present invention; and

[0021]FIG. 6 is an isometric view of an access flooring system showing a plurality of pedestals with stringers for supporting a floor panel in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] Reference is made to FIGS. 1 and 2, which illustrate an access floor panel 10 made in accordance with a first preferred embodiment of the present invention, and which will be used for the purposes of describing the operational aspects of the invention. Floor panel 10 is for use in access floor systems, and may have any suitable shape therefor. For example, floor panel 10 may have a generally rectangular shape. By rectangular, it is contemplated that floor panel 10 may be square or may be oblong (ie. it may have four equal-length sides or four sides wherein one pair of opposing sides is longer than the other pair of opposing sides). Furthermore, having a rectangular shape means, for the purposes of this disclosure, that the floor panel 10 has a rectangular shape when viewed by persons who are walking on it. In the embodiment shown in FIG. 1, the floor panel 10 is shown as square shaped.

[0023] Floor panel 10 includes a bottom pan 12, a core 14 (shown in FIG. 2) and may optionally include a top pan 16. Bottom pan 12 may have any suitable shape, such as, for example, a generally rectangular shape, or more specifically, a square shape. Bottom pan 12 may be made out of any suitably strong, resilient, tensile material, such as, for example, formed steel. Bottom pan 12 includes a plate 20 and may optionally include sidewalls 22 attached thereto about the periphery of plate 20. Sidewalls 22 substantially surround core 14.

[0024] Reference is made to FIG. 2, which shows a side view of floor panel 10. Core 14 has a core body 17, which is made from a composite material that is a mixture of a chemically mineralized fibrous material 18 mixed with a cement binder 19. This material provides strength to core 14 and to floor panel 10, but is relatively light, as is thus easy to manoeuver and install, and to remove for access to under-floor services. Furthermore, this material provides good sound deadening properties to the floor panel 10, making the floor panel 10 quiet to walk on. Furthermore, this material is relatively easy to machine, facilitating the manufacture of floor panels 10.

[0025] The material may begin generally as a fibre/cement paste, which is molded and cured. The mineralized fibrous material could include mineralized and neutralized softwood or hardwood shavings, vegetable or textile fibres, coco fibres, grasses, plant fibres, reed and inorganic fibres, such as asbestos, glass wool, rock wool and vermiculite. Various cement binders may be used, such as hydraulic cement and hydraulic lime. A preferred core material is known by the trademark DURISOL™, a product of Durisol Materials Limited. DURISOL™ is typically used as a sound absorbent material in highway acoustical barriers to protect neighbourhoods that border highways from traffic noise. However, DURISOL™ has many of the properties described above that render it advantageous for use as a core material in access floor panel 10. It is relatively strong, yet light. It is impervious to moisture and has good sound deadening characteristics. It is also virtually incombustible.

[0026] Core 14 may have any suitable shape, such as a rectangular shape, or more specifically, a square shape. Core 14 has a top face 23, a bottom face 24 and a plurality of side edge faces 25. For embodiments wherein core 14 is oblong, there are two pairs of opposing side edge faces, wherein one pair is longer than the other pair. For embodiments wherein core 14 is square-shaped, there are four equal-length side edge faces.

[0027] Core 14 may be fabricated in several ways. The fibre/cement paste may be prepared and molded into a square piece which is core 14, and which has the correct dimensions to fit into bottom pan 12. Alternatively, the paste may be molded into a large sheet and then cut to appropriate dimensions for installing into bottom pan 12. Alternatively, an appropriate amount of paste may be placed directly into bottom pan 12, and then pressed to the desired shape using top pan 16 and cured. If the uncured paste is placed directly in bottom pan 12 for molding and curing, bottom pan 12 preferably has no corner gaps or other leakage points. If the paste is cured directly in bottom pan 12, the top surface 23 may require machining to achieve a surface of suitable height and flatness.

[0028] When a perpendicular force is exerted on panel 10, such as, for example, by a person standing on panel 10, panel 10 incurs a bending stress, such that a bottom portion of panel 10 is placed in tension and an upper portion of panel 10 is placed in compression. A perpendicular force, for the purposes of this disclosure, refers to any force that includes a component that is perpendicular to the plane of floor panel 10, such as from a person standing or walking on floor panel 10.

[0029] Core 14 may optionally include reinforcing bars 26, which are preferably encased in mortar shells 27 to strengthen core 14. The number of reinforcing bars 26 that may be used depends on the application, and the bars 26 may extend parallelly, orthogonally, or at other angles relative to each other. Reinforcing bars 26 share the tensile stresses incurred by the core body 17, and thus reduce the tensile stresses incurred by the bottom portion of the core body 17. Thus, the reinforcing bars 26 improve the load bearing capability of floor panel 10. Preferably, reinforcing bars 26 are positioned closer the bottom face 24 of core 14, for improved strengthening effect. While a plurality of reinforcing bars 26 is preferable, a single reinforcing bar 26 may be used.

[0030] Top pan 16 includes a plate 30, and may further include peripheral flaps 32 which fold over and overlap with sidewalls 22 of bottom pan 12. It is not necessary for the overlapping region between flaps 32 and sidewalls 22 to be able to support any perpendicular force.

[0031] Reference is made to FIG. 3, which shows floor panel 10, having a core 14′, which is similar to core 14, but which includes a plurality of optional exterior reinforcing bars 26′. Exterior reinforcing bars 26′ reduce bending stresses on the core body 17′ from a perpendicular force such as, for example, a person standing on the floor panel 10′, by sharing tensile stresses with the core body 17′, in a similar fashion to reinforcing bars 26. Exterior reinforcing bars 26′, however, are fixedly secured to the exterior of core 14′. Bars 26′ may be generally C-shaped in cross-section, as shown, and may be cast directly with the core body 17′, extending along side edge faces 25. Alternatively, the core body 17′ may be cured and then machined as necessary for receiving reinforcing bars 26′, which may be pressed thereon or otherwise mounted. Reinforcing bars 26′ may be made from any suitably strong, resilient material, such as a heavy gauge steel.

[0032] Core 14′ may include a single exterior reinforcing bar 26′ for some improvement in the load bearing capacity of floor panel 10′. However, for rectangular floor panels 10′, it is advantageous to include exterior reinforcing bars 26′ on at least a pair of opposing side edge faces 25, and it is more preferably to include an exterior reinforcing bars 26′ on each side edge face 25 of a core 14′.

[0033] Where the core 14′ includes exterior reinforcing bars 26′, the bottom pan 12′ may be free of sidewalls, and the top pan 16′may be free of peripheral flaps.

[0034] Reference is made to FIG. 4, which shows a portion of floor panel 10. Bottom pan 12 and core 14 may optionally include a plurality of interconnecting recesses 28 and protrusions 29, which mate with each other to help strengthen the bond with core 14. The recesses 28 and keys 29 may have any suitable mating shapes. The recesses 28 may be grooves and the protrusions may be keys, or alternatively, the recesses 28 may be conical, and the protrustions 29 may be cone-shaped bosses. The recesses 28 may be on the bottom pan 12, and the protrusions 29 may be on the core 14, or vice versa. As a further alternative, recesses 28 and protrusions 29 may be on one of the core 14 and the bottom pan 12 for mating with complementary protrusions 29 and recesses 28 on the other. This is particularly effective and easy to manufacture if core 14 is molded directly inside bottom pan 12 so that protrusions 28 and/or recesses 29 in core 14 form when the mixture for core body 17 is placed into the bottom pan 12. If recesses 28 and protrusions 29 are incorporated into floor panel 10, the use of hot melt glue or other adhesive may not be necessary, and may be selected for use, depending on the particular application.

[0035] The same structure and technique of using recesses 28 and protrusions 29 for securing core 14 to bottom pan 12 may be used to secure top pan 16 to core 14, however, consideration should be given to make the walking surface (the uppwards facing surface) of top pan 16 usable for walking thereon. Thus, it is preferable for top pan 16 to include protrusions 29 that mate with recesses 28 in core 14, and for protrusions 29 to have a suitable width and depth so that their ‘inverse’ shapes that appear on the walking surface of the top pan 16 do not interfere with walking thereon.

[0036] The properties of panel 10 such as strength, weight and sound deadening can be modified or selected by controlling the size and length of the fibres used in the core material, the ratios of mix components in the core material, the density of the core material, finished core thickness and the covering steel thicknesses. Also, autoclaving may be performed on core 14 to assist in curing of the material, thereby enhancing certain panel properties.

[0037] A method in accordance with the present invention, of making access floor panel 10 will now be described. A pre-cured core 14 may be installed in bottom pan 12, and an appropriate securing means, such as hot melt glue is applied to secure plate 20 of bottom pan 12 to core 14. As well, the securing means may also be used to secure plate 30 of top pan 16 to core 14, so that core 14 is sandwiched between pans 12 and 16 and held firmly in place.

[0038] Fixedly securing core 14 to plate 20 of bottom pan 12 permits plate 20 to share tensile stresses on the lower portion of core 14 and thus improves the load bearing capability of core 14 in a similar fashion to reinforcing bars 26.

[0039] Reference is made to FIG. 5, which shows a plurality of pedestals 34 supporting a plurality of access floor panels 10. Together, the access floor panels 10 and the pedestals 34 form an access flooring system 36.

[0040] Pedestal 34 includes a vertical support post 42, a panel support piece 44 and a base 48. Base 48 rests on a lower floor 50. Individual panels 10 are supported on the corners of the bottom pan 12 by panel support 44.

[0041] As shown in FIG. 6, the pedestals 34 may optionally be interconnected by a plurality of elongate stringers 38, which provide further support for panels 10. Stringers 38 serve to further support panels 10 along the periphery of the plate 20 of bottom pan 12.

[0042] Alternative stringers (not shown) having an inverted T-shaped section may also be used to provide enhanced support and may also be used to separate and confine adjacent panels 10.

[0043] While a specific type of joint has been disclosed between top pan 16 and bottom pan 12, any type of joint known in the art may be used.

[0044] Fabricating a floor panel with a core made from a fibre/cement mixture provides a panel that is strong, yet lightweight, that is virtually unaffected by moisture, and that provides good sound deadening characteristics.

[0045] As will be apparent to persons skilled in the art, various modifications and adaptations of the systems and methods described above are possible without departure from the present invention, the scope of which is defined in the appended claims. 

1. An access floor panel, comprising: a bottom pan including a plate; a core including a core body made from a mixture of a mineralized fibrous aggregate and a cement binder, said core being secured to said plate.
 2. An access floor panel as in claim 1, wherein said bottom pan further comprises a sidewall that projects upwards from said plate and surrounds said core.
 3. An access floor panel as in claim 1, wherein said core body is made from DURISOL™.
 4. An access floor panel as in claim 1, further comprising a top pan, said top pan being attached to at least one of said bottom pan and said core.
 5. An access floor panel as in claim 1, wherein said plate is a resilient tensile member and said core is fixedly secured to said plate so that said core body and said plate share tensile stresses incurred by said core when a perpendicular force is exerted on said core.
 6. An access floor panel as in claim 1, wherein said core is secured to said plate with a hot melt glue.
 7. An access floor panel as in claim 2, wherein said mixture is a paste that is adapted to be molded and cured in said bottom pan.
 8. An access floor panel as in claim 1, further comprising at least one anchor mounted to said core and extending outwardly from the surface of said core, wherein said bottom pan further includes at least one anchor mating portion for mating with said at least one anchor to secure said core and said bottom pan together.
 9. An access floor panel as in claim 1, wherein said core further includes at least one reinforcing bar positioned within said core body so that said core body and said at least one reinforcing bar share tensile stresses incurred by said core when a perpendicular force is exerted on said core.
 10. An access floor panel as in claim 1, wherein said core body has a top face, a bottom face and a plurality of side edge faces extending between said top and bottom faces, and said core further includes at least one exterior reinforcing bar, said at least one exterior reinforcing bar being fixedly secured to said core body and extending along at least one side edge face of said core body so that said core body and said at least one exterior reinforcing bar share tensile stresses incurred by said core when a perpendicular force is exerted on said core.
 11. An access floor panel as in claim 10, wherein said core body is generally rectangular, and said core further includes two exterior reinforcing bars that are fixedly secured to said core body along two opposing side edge faces of said core body.
 12. An access floor panel as in claim 10, wherein said core further includes one of said at least one exterior reinforcing bar, fixedly secured to said core body along each side edge face of said core body.
 13. An access floor panel as in claim 1, wherein at least one of said core and said plate has at least one protrusion, and the other of said core and said plate has a recess for mating with said protrusion to secure said core to said plate.
 14. A method of making an access floor panel, the method comprising: putting a core material into a bottom pan, said core material comprising a mixture of a mineralized fibrous aggregate and a cement binder; and molding and curing said core material into a core in said bottom pan.
 15. The method as in claim 14, further comprising the step of securing a top pan to said core.
 16. The method as in claim 14, wherein the securing step is executed with a hot melt glue.
 17. A method of making an access floor panel, the method comprising: providing a pre-cured core that is adapted to fit with a bottom pan, said core comprising a mixture of a mineralized fibrous aggregate and a cement binder; and securing said core to said bottom pan.
 18. The method as in claim 17, further comprising the step of securing a top pan to said core.
 19. The method as in claim 17, wherein the securing step is executed with a hot melt glue.
 20. An access flooring system comprising a plurality of access floor panels as claimed in claim 1; and a plurality of pedestals for supporting said access floor panels above a lower floor, each said pedestals including a base that is mountable to said lower floor, a support post extending upwards from said base and a panel support piece mounted to said support post for receiving and supporting a portion of at least one of said plurality of access floor panels. 